Rose Elizabeth Cleveland (June 13, 1846 – November 22, 1918) was an American author and lecturer. She was acting First Lady of the United States from 1885 to 1886, during the presidency of her brother, Grover Cleveland, who married in 1886.

Receiving an advanced education in her youth, Cleveland defied gender norms and pursued a career in a variety of literary and academic positions. When her unmarried brother was elected president, she acted in the role of first lady until his marriage to Frances Folsom. She used the role of first lady to galvanize support for women's suffrage, expressing little interest in more typical household management tasks.

After leaving the White House, Cleveland wrote several fiction and nonfiction works, many relating to women's rights. She was editor of a literary magazine for several months, and she continued teaching and lecturing. She met Evangeline Marrs Simpson in 1889, and the two became romantic partners, interrupted for several years by Simpson's marriage to Henry Benjamin Whipple. After reuniting, they moved to Italy in 1910, where Cleveland spent her final years helping war refugees during World War I and then Spanish flu patients, before contracting the disease herself and dying in 1918.

Rose Elizabeth Cleveland was born in Fayetteville, New York, on June 13, 1846. The ninth and youngest child of Reverend Richard Falley Cleveland and Ann Neal Cleveland, she was known as "Libby" within her family. The Cleveland family arrived in the present-day United States with Moses Cleveland, who settled in the Massachusetts Bay Colony in 1635 after emigrating from Ipswich, England. From her mother's side, Cleveland was descended from Anglo-Irish and German Quaker families. As a young child, Cleveland rejected gender norms where she encountered them and engaged in an active lifestyle outdoors. Cleveland and her siblings were raised as Presbyterian, and she would remain devoted to the religion her entire life. The Clevelands were poor, and their father struggled to support the family. In 1850, he moved the family to Clinton in New York's Oneida County so he could work as a district secretary for the American Home Missionary Society. In 1853, they moved to Holland Patent, New York. Their father died shortly afterward; Rose was seven years old. She stayed in their Holland Patent home, called "The Weeds", with her mother as her siblings began moving out.

By the start of the American Civil War, when Cleveland was 14 years old, all of her siblings had moved out except for her 18-year-old sister Susan. Their brother Grover paid for them to go to college. Cleveland attended Houghton Seminary in Clinton from 1864 to 1866 and studied Greek and Latin literature. Shortly after graduating, she took a position at the school teaching history and literature. The following year, in 1867, she taught literature, math, and Latin at the Lafayette Collegiate Institute in Lafayette, Indiana. She then taught at a girls school in Muncy, Pennsylvania, in the late 1860s before returning to "The Weeds" in Holland Patent. She returned to Houghton Academy to again teach history, and she also taught Sunday school. She taught American history in New York City. Cleveland also delivered public lectures in the state of New York, speaking about topics including history and women's rights. The Magazine of American History published her lectures, and she was active in its editorial process.

Two of Cleveland's brothers, Frederick and Louis, were lost at sea in 1872 while on a ship from Nassau. Eventually, her time in Holland Patent was spent caring for her mother until her death in 1882. Cleveland inherited The Weeds from her mother. Her brother Grover was elected to be the governor of New York in 1882. Cleveland declined a teaching job in New York City so that she could assist him at the Executive Mansion. During this time, she published her first two poems in The Independent. Cleveland was with her brother at the Executive Mansion when he learned that he had been elected president, and she stood by him during his presidential inauguration.

When Grover became president of the United States in 1885, he had no wife to serve as first lady, so he asked Cleveland to fulfill the role. She accepted the position despite having little interest in it; she preferred academic life to social life. As was typical of first ladies of the time, Cleveland was responsible purely for domestic aspects of the White House, including the organization of social events. She most commonly held receptions in the Blue Room. Cleveland grew bored with White House reception lines and once said that to pass the time she would conjugate Greek verbs in her head. She was sometimes assisted by her sister, Mary Hoyt.

Cleveland was more academically-inclined than most women of her era. She was not interested in the small talk expected of her during social events, and writer Harry Thurston Peck said that her conversations were "decidedly allusive and interspersed with classical quotations". Her education served her well in the White House, where knowledge of history and languages was an asset when speaking to dignitaries from around the world. Shortly after her time as acting first lady began, Cleveland published her first book: George Eliot's Poetry, and Other Studies. The press did not treat her seriously as an intellectual because she was a woman, but her national renown as first lady helped sales, and she ultimately earned $25,000 (equivalent to $875,000 in 2024) in royalties across twelve published editions.